摘要
如何保持复杂地层中斜井或水平井井孔的稳定,是油气田钻井和生产期间的重要研究课题。从横观各向同性本构模型出发,考虑岩石拉伸强度的方向性以及层状岩石中存在剪切强度薄弱面(如节理、断层、岩层界面等),在广义平面应变假定条件下,提出了一种可以分析任意走向层状岩石中井孔稳定性问题的二维有限元数值计算模型和计算方法。对复杂地质构造的层状岩石中井孔稳定性的二维有限元数值计算表明,岩层中薄弱面上出现的剪切破坏是导致井孔失稳的主要原因。对于特定的地质条件,用该模型可以快速预测现场钻井时的安全钻井压力,也可以分析和显示井孔周围破坏区的形状和范围。
It is an important project to keep the wellbore stable for exploration and development. Based on transversely isotropic constitutive relations and the generalized plane strain deformation assumption, a two-dimensional finite element computational model considering the influence of directional tensile strength and shear strength on weak planes is proposed to analyze the stability of inclined borehole in arbitrary dip direction of bedded formation. The computation results imply that it is possible to analyze the wellbore stability in complex geologic conditions and to predict the safe well pressure rapidly in drilling problem by using the model. The numerical result suggests that the main cause of the wellbore instability is the shear failure induced by weak plane.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2004年第4期89-92,98,共5页
Petroleum Exploration and Development
关键词
稳定性
横观各向同性
数值分析
stability
transversely isotropic
numerical analysis
